Bilateral simultaneous cavernous sinus sampling using corticotropin-releasing hormone in the evaluation of Cushing disease.

PURPOSE To determine whether bilateral, simultaneous, cavernous sinus sampling after corticotropin-releasing hormone (CRH) stimulation offers as accurate detection and lateralization of Cushing disease as inferior petrosal sinus sampling does. METHODS Seventeen consecutive patients with hypercortisolism and with high-dose dexamethasone suppression test results suggesting Cushing disease underwent bilateral cavenous sinus sampling with CRH stimulation. The diagnosis of Cushing disease was established in all patients by histologic examination or, if no tumor was found at surgery, by subtotal resection of the gland or radiation therapy resulting in eventual hypocortisolism or normal adrenal function and clinical remission. RESULTS The sensitivity of cavenous sinus sampling with and without CRH in detecting Cushing disease was 94% and 71%, respectively. The abnormal side of the pituitary was correctly identified in all patients who had criteria for lateralization, yielding a positive predictive value of 100%. CONCLUSIONS This small series suggests that cavernous sinus sampling with CRH is as accurate as inferior petrosal sinus sampling in detecting Cushing disease and perhaps more accurate in lateralizing the abnormality within the pituitary gland.